Constipation-predominant irritable bowel syndrome (IBS-C) is a condition characterized by chronic constipation with accompanying abdominal pain. It is a subtype of irritable bowel syndrome (IBS) and about a third of people with IBS develop type IBS-C.
IBS-C is one of the functional gastrointestinal disorders (FGD), which are gastrointestinal (GI) disorders that cause signs and symptoms for no known cause, despite standard diagnostic tests. These disorders can cause great distress. Changes in diet, supplements, medications, and behavioral interventions can reduce symptoms.
The predominant symptoms of IBS-C are frequent constipation, accompanied by pain during bowel movements .
One or two bowel movements a day is normal, but less than one bowel movement a day is also normal. Generally speaking, characteristics that indicate constipation include:
- You have a bowel movement less than three times a week.
- Hard or rough stools
- The need to strain during bowel movements.
The Rome IV Criteria define FGD based on specific signs and symptoms. According to the Rome IV criteria, SRK-Z is specifically defined as a condition in which:
- Pain-related constipation occurs at least three days a month.
- Symptoms have persisted for the past three months.
- At least 25% of stools are hard and less than 25% are soft.
In addition to the criteria for IBS-C, there are a few other symptoms that can occur if you have constipation-predominant IBS.
Common symptoms of IBS-C include:
With IBS-C, loose stools are rare unless a laxative is used.
IBS-C for chronic idiopathic constipation (CIC)
IBS-C and chronic idiopathic constipation (also known as functional constipation) share many symptoms. According to the Rome IV criteria, the biggest difference is that IBS-C causes abdominal pain and discomfort along with constipation, whereas idiopathic constipation is usually painless.
Gastroenterologists wonder if these two conditions are manifestations of the same disorder within the same spectrum of diseases, rather than two completely separate disorders. However, the two conditions tend to respond to different treatments, suggesting that they can be accurately thought of as two different conditions. At the moment, the answer is not entirely clear.
The cause of IBS-Z is unknown. The symptoms are due to the digestive system not working properly, but there is no apparent reason for this. Dysynergic defecation , which is a dysfunction of the pelvic floor muscles, is usually present in people with IBS-C .
IBS-C is traditionally a diagnosis of exclusion, meaning it is only diagnosed after ruling out other disorders that may be causing your symptoms. However, diagnostic guidelines issued in 2021 by the American College of Gastroenterology (ACG) aim to make a positive diagnosis.
ACG claims that the diagnostic method it recommends will speed up the process, meaning you'll get the right treatment faster. It is not yet clear how these guidelines will change the typical healthcare provider's IBS diagnosis process. Rest assured that any method will help you make an accurate diagnosis.
Diagnosis of exceptions
In the method above, if your healthcare provider suspects IBS-C, they will likely get a list of your symptoms, examine you, do a blood test, and analyze a stool sample. Other tests, including imaging and interventional tests such as colonoscopy , may be recommended based on your symptoms and medical history.
If your symptoms meet the diagnostic criteria for IBS-C and there is no evidence of anxiety symptoms or other medical conditions, you may be diagnosed with IBS-C.
The ACG recommended method of diagnosis includes looking at your medical history and physical exam, as well as the main symptoms, including:
- Abdominal pain
- Modified bowel habits
- At least six months duration of symptoms.
- Lack of warning signs of other possible conditions.
- Possible examination of anorectal physiology if pelvic floor disease is suspected or if constipation does not respond to standard treatment
For IBS-C, no further testing is recommended.
The ACG treatment protocol for IBS-C includes dietary changes, supplements, prescription medications, and lifestyle / behavior changes.
Diet and supplements
- Diet changes : A short-term trial of a low-FODMAP diet can help you identify the foods that are contributing to your symptoms.
- Fiber : Slowly increasing the amount of fiber, especially soluble fiber, in your diet (or in supplements ) can promote more frequent bowel movements.
- Peppermint Oil : Enteric-coated peppermint oil capsules can help relax your intestinal muscles, reduce pain and inflammation, and kill harmful bacteria.
- Amitiza (Lubiproston) : Increases the secretion of fluid in the intestines.
- Linzess (Linaclotide) or Trulance (Plecanatid) : increases bowel movement.
- Zelnorm (tegaserod) : accelerates digestion and reduces hypersensitivity of the digestive system (recommended for women under 65 without risk factors for cardiovascular disease and lack of response to other medications)
- Tricyclic antidepressants : Prescription drugs that can affect the nerves of the gastrointestinal tract by altering the activity of the neurotransmitters norepinephrine and dopamine .
The ACG argues that some of the common treatments for IBS-C do not have sufficient evidence of their effectiveness to be recommended. This includes: